【摘要】 利用高分辨电子动量谱仪测量了乙醇分子外价轨道的电离能谱,通过对一系列角度关联的电离能谱进行解谱,获得了各个电离能峰对应的分子轨道电子动量分布.利用密度泛函理论方法计算了乙醇分子两种构象异构体的轨道电子动量分布,通过与实验结果进行比较,发现实验测量的电离能为14.5和15.2 eV能峰对应的电子动量分布分别与理论计算的单个构象异构体trans 8a′和gauche 9a轨道电子动量分布符合较好.更多还原

【Abstract】 The outer-valence binding energy spectra of ethanol in the energy range of 9-21 eV are measured by a high-resolution electron momentum spectrometer at an impact energy of 2.5 keV plus the binding energy.The electron momentum distributions for the ionization peaks corresponding to the outer-valence orbitals are obtained by deconvoluting a series of azimuthal angular correlated binding energy spectra.Comparison is made with the theoretical calculations for two conformers,trans and gauche,coexisting in the gas phase of ethanol at the level of B3 LYP density functional theory with aug-cc-pVTZ basis sets.It is found that the measured electron momentum distributions for the peaks at 14.5 and 15.2 eV are in good agreement with the theoretical electron momentum distributions for the molecular orbitals of individual conformers(i.e.,8a’ of trans and 9a of gauche),but not in accordance with the thermally averaged ones.It demonstrates that the high-resolution electron momentum spectrometer,by inspecting the molecular electronic structure,is a promising technique to identify different conformers in a mixed sample.更多还原